Multi-color effects in textiles have heretofore been obtained either by blending colored raw material prior to spinning or by using dyed yarn of different colors in weaving, knitting or twisting. Another known procedure is to blend raw fibers of different compositions together, then place them in a single dye bath to obtain a multi-color effect. The different compositions will dye differently creating a two tone or multi-colored effect. Other procedures allow obtaining a tone on tone effect of differential shading by applying a special treatment, such as acetylation, on one part of fibers contained in the yarn, prior to spinning which prevents the treated fiber from taking up certain dyestuffs.
Another way to obtain two tone or multi-colored effects is by increasing the affinity of some of the fibers with respect to certain dyestuffs. One such procedure increases affinity by a chlorination treatment. Other procedures to affect dye affinity of fibers to certain dyestuffs use strongly acidic or alkaline baths. Still other treatment procedures use oxidizing treatments with metallic salts.
Another known treatment for obtaining multi-colored effects on fiber material uses a chrome based mordant to treat fibers that are then blended with untreated fibers. The known procedures for using a chrome based mordant do not fix the mordant to the fibers well. This results in the presence of residual mordant in the bath, which in turn lessens the desired two tone coloring effect.
The known two tone or multi-color dyeing procedures do not produce a highly distinct color differentiation. In addition, these treatments required to produce two-tone or multi-colored effects adversely react with the fibers causing damage to the fibers.
The present invention enables dyeing fibers of the same composition in a single bath to obtain a two tone or multi-color effect without use of mineral reducing agents or other chemicals that harm the quality of the fiber. The fixation of a mordant to the pretreated fibers in the present invention is substantially complete to the extent that no residual dye remains in the dye bath to effect the coloring of untreated fiber, allowing superior light fastness, reproducibility, and contrast.